Fender Sidekick 35R transformer specs needed

[Strick]

New guy here.  Trying to replace a dead power transformer in this SS Fender amp (Sidekick 35 Reverb).  The Sidekick series appears to have been built for a few years starting in the early '80s.  Fender says that no parts list is available but they did email a schematic.  Problem is that the schematic doesn't show the transformer secondary AC voltage or the DC voltage at the output of the bridge & caps.  The only identification on the dead transformer is "TCE66 086" and "30UC".  I could not find anything by searching on various combinations of this information.  I've Googled and Bing-ed and read forums and applied due diligence in my research to get this sorted. 

I found a schematic for a Fender Sidekick 35W Bass from the same amp series that indicates +/-31VDC at the DC test points after the rectifier "box".  I'm assuming that the box is a full-wave bridge rectifier and I've backed up from the 31 volts using the 1.414 factor.  That works out to about 22VAC input to the bridge.  48VCT (24-0-24) at 2A transformers seem to be more common but that would be nearly 34VDC after the bridge.  Is that too high? 

Does this sound like a reasonable way to try and get this thing going again?  Is the 31V guess based on the 35B a sound way to proceed?  Schematics from the 35R and 35B are attached.  Comments are welcome.

Thanks for your time,
Strick

[J M Fahey]

Congratulations, Strick, excellent deductive powers.
Besides that, you certainly did your homework.
The two amps are clearly the same, that´s why they didn't repeat some labels.
Your +/-34V will be a little on the high side, I'd rather go a little too low, for safety reasons, but if you already have a 48VCT 2A transformer lying around, give it a try.
Anyway you have to sort out why the power transformer was blown in the first place.
A shorted output combined to an oversized or bypassed fuse would be a most likely suspect for me.

[Brymus]

Hey Strick -Nice work,you figured that out rather nicely.
Maybe this will help.
I bought a 42VCT 80VA toriodal transformer from APEX JR for 10$
I think that would be just what your looking for,hope this helps and let us know what happens.
http://www.apexjr.com/index.html
click on the picture of the transformer.

[Brymus]

Hey Strick I was looking at your schematic and noticed its not a chip amp.
What transistors are they using ? TIP31 type set-up?
Sorry its off topic just curious...

[Strick]

J M Fahey and Brymus:

Thanks for your comments and suggestions.  I'll definitely be looking at Apex for a transformer.  The toroids look promising and it should be fairly easy to mount one in the amp.  I'll start trying to sort out the reason for the transformer failure and any tips about that search would be welcome.

I believe the finals are 2SD-613E's which cross to an ECG377.  I don't know how this would compare to a TIP31 set.  Oh, and I've just recently learned of the chipamps and will look to building one soon. 

Again, thanks to both of you and best regards,
Strick

[Enzo]

Please, wean yourself from NTE.   No reason to cross a 2SD613 to NTE, MCM sells real 2SD613 for $1.11 each.  But the 100v 6A transistor is also pretty much the same thing as a TIP41C.  Mouser sells TIP 41C for 40 cents each  The TIP41C has a higher power dissipation that the D613 too.

[J M Fahey]

Good suggestion.
Unless searching for a *very* common transistor, such as a TIPxxx , it usually pays doing a little research using *parameters*, that is meeting or exceeding voltage, power , current and Beta (dc gain); obviously also matching case specs.
That`s the easiest part, most power transistors using TO220 ("Plastic TO66", TIP31 size) or TO218 ("Plastic TO3", TIP142 size), not forgetting old faithful metallic TO3 cases (2N3055 size)
Some Japanese transistors, specially Sanken or Toshiba types, use *huge* , "chocolate cookie" 2-screw cases which unfortunately ask for same-type replacement or a lot of brain surgery to mount something else.